A "yes" vote would extend a tax that started in 2003 and is expected to pay for the renovation or replacement of 94 schools, from Edgewater High to Dream Lake Elementary, by the time it runs out at the end of next year.

If the tax is renewed, the School Board has agreed to first complete an additional 42 projects, such as Union Park Elementary and four county tech schools, from the initial list. Sinking sales-tax proceeds during the recession, increased construction costs, greater space needs because of state class-size laws and reduced state funding for school facilities all played a role in the shortfall.

After completing the original list, the new funds would be used to tackle an additional 59 schools, including Boone, Colonial and Winter Park high schools, that didn't make the list 12 years ago.

Batchelor has led the effort to gain bipartisan backing and has successfully tallied endorsements from a wide range of chambers of commerce, business groups and local leaders.

"It's an incredibly important investment in our community, an incredibly important investment in our kids," said Tico Perez, a lawyer, political activist and commentator who is supporting Change 4 Kids as an honorary co-chair. With an anticipated 55 percent of the tax paid by tourists, the half-penny would provide not only new schools but improved technology districtwide.

Opposition has been muted so far, but Doug Guetzloe, chairman of Ax the Tax, said the group will use social media, phone calls, door-to-door visits and yard signs to oppose the measure.

"Payback time," said Guetzloe, whose group unsuccessfully opposed the tax in 2002.

"We expect to win," he said, because of the district's "poor record" using the current tax money. A series of audits starting in 2002 found financial problems in the facilities department. That reduced public confidence, but construction has run smoothly since the district tapped John Morris to overhaul the department in 2011.

The sales-tax rate in Orange County is 61/2 cents. If the referendum fails, it would drop to 6 cents in 2016. In November, Orange County schools also plan to ask voters to renew a 1-mill special property tax that since 2010 has been used maintain more than 700 teacher positions, keep art in schools and preserve sports.

In Seminole County, voters approved in May a 1-cent sales-tax hike to pay for roads, trails and schools.

Batchelor said he is confident the district has turned a corner and that the money would be put to good use.

"We're picking up a lot of support to launch a full-bore campaign," Batchelor said. Change 4 Kids has raised more than $350,000 so far, largely from theme parks, the construction industry and Florida Hospital.

That money will pay for the advertising campaign that backers hope will reach a broad swath of potential primary voters.

The first ads voters will see are electronic billboards next week in 10 locations, including along the East-West Expressway; East and West Colonial Drive; Interstate 4; Orange Avenue; and Semoran Boulevard. The campaign will also have three standing billboards donated by ClearChannel.

They will encourage voters to "keep giving a little" and to vote yes Aug. 26.

Postcards are being sent to absentee voters. And Batchelor said other mailers will target communities with schools that would be replaced or renovated if the tax is renewed.

Earnest DeLoach, a local lawyer with small children, said he worries about economic impacts if the tax doesn't get extended. "The first thing people ask is: 'What are the schools like?'" he said.

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